[018/119] sound: rawmidi: fix checking of O_APPEND when opening MIDI device

Greg KH
2009-12-07T00:12:45Z

[-- Attachment #1: sound-rawmidi-fix-checking-of-o_append-when-opening-midi-device.patch --]
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2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
From: Clemens Ladisch <clemens@ladisch.de>

commit 16fb109644b5644e42ececeff644514de6f4bd03 upstream.

Commit 9a1b64caac82aa02cb74587ffc798e6f42c6170a in 2.6.30 dropped the
check that a substream must already have been opened with O_APPEND to be
able to open it a second time.

This would make it possible for a substream to be switched to append
mode, which would mean that non-atomic writes would fail unexpectedly.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
sound/core/rawmidi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -248,7 +248,8 @@ static int assign_substream(struct snd_r
list_for_each_entry(substream, &s->substreams, list) {
if (substream->opened) {
if (stream == SNDRV_RAWMIDI_STREAM_INPUT ||
- !(mode & SNDRV_RAWMIDI_LFLG_APPEND))
+ !(mode & SNDRV_RAWMIDI_LFLG_APPEND) ||
+ !substream->append)
continue;
}
if (subdevice < 0 || subdevice == substream->number) {